In the early 1860's, Whitley Denton, a Mill Superintendent at a company called The Michigan Central Woolen Company, in Centerville, Mich., designed an improved form of the one-piece union suit by constructing a pair of booties and attaching them to the ankles of the union suit to create a garment for young children. At that time, rubber buttons and button holes were employed to provide the necessary closure for the garment. Various forms of the garment, e.g., as sleepers, playsuits and the like, have been sold over the decades all over the world. Subsequent developments of the sliding fastener commonly known as a "zipper" have provided improvement to the basic idea. More recently, the general availability of pressure-responsive fastening means, commonly known as "Velcro" (.TM.), have provided other alternatives.
A highly desirable feature of such a garment, which is often worn next to the skin by a user, is the avoidance of unnecessary seams in the body portion of the garment, especially at the sides and the back. For babies and younger children who may be picked up by adults by being grasped at their sides, and who may often lie for prolong periods on their backs, seams at the sides and the back are particulary unwelcome. The provision of a one-piece body portion for such a garment is, therefore, almost a necessity.
If the garment is to be employed as an item of thermal underwear, it is most likely to be formed of knitted fabric, which, typically, does not have a pronounced directional orientation in terms of strength and/or stiffness. On the other hand, if the garment is intended to be a warm playsuit for a child, the fabric may be of the woven type, i.e., one in which the warp end and the woof threads intersect othogonally and inherently generate preferred directions of stiffness. The handling of patterned elements of knitted or woven fabrics may therefore have to be different, depending on the manner in which attachment of the closure element is to be effected. If the closure element is one which includes a sliding fastener, e.g., the conventional "zipper", it will be provided most conveniently in the form of an elongate tape or ribbon-like element stored on a reel. Small relatively hard engaging elements of the zipper structure are themselves connected to each of two elongate parallel cloth strips which, while flexible, typically do not have the stretch which knitted fabrics inherently possess. Consequently, the attachment of such a closure element to knitted fabric requires careful handling, to avoid disparate tensions on the knitted fabric and the closure element. Woven fabrics, however, may be somewhat easier to handle, depending on the orientation of the structural threads of the woven fabric.
Numerous machines, and methods for using the same, are available for attaching elongate, sliding-fastener type, closure elements to both knitted and woven fabrics. For convenience, the fabric edges are conventionally passed through folder elements which fold the extreme edge portions of the fabric so that the elongate fastener element is sewn thereto in a single pass under two cooperating needles which provide two parallel lines of stitching to the hemmed fabric as the hemmed edges are attached to the closure element. This is relatively easy when two separate pieces of fabric are to be attached to the same elongate closure element. Examples of apparatus and methods for such work include those disclosed in U.S. Pat. No. 4,623,792 to Yoshioka, titled "Apparatus for Sewing Slide Fasteners to Pairs of Fabric Pieces".
The handling problem is somewhat different if a one-piece fabric element is to have two of its single edges connected to an elongate fastening element like a zipper to create an openable closure thereby. U.S. Pat. No. 4,956,879 to Adams, titled "Garment Having Seamless Body" discloses a method for sewing a garment having a seamless body portion. As best seen in FIG. 1 of this application (a reproduction of FIG. 6 of Adams), a one-piece body component 30 is placed "face down" on table 40 of sewing machine 42 behind, i.e., downstream of, a pair of needles 44. The upper end of the body portion of fabric piece 30 faces the operator initially. A ring-shaped needle guard 46 surrounds needles 44 to prevent the fabric of piece 30 from tangling with the needles during a step in which the fabric is pulled toward the operator, turned and fed through a folder element 48 disposed upstream of the needles. Folder element 48 turns the two edges 30a and 30b of the fabric piece 30 to form respective hems immediately prior to stitching by the needles. As best seen in FIG. 2 of this application (a reproduction of FIG. 7 of Adams), a length of slide fastener tape 56 is conveniently dispensed from a roll 58 thereof through a guide and tension attachment 60, to a point downstream with respect to folder element 48 but upstream of needles 44. Thus, when the folded fabric hems are stitched by the needles 44, the slide fastener tape 56 is simultaneously stitched to the hems, thereby forming a closure 66.
In the method of Adams, considerable and careful manipulation of the fabric piece 30 is required. Specifically, the upper ends of side edges 30a and 30b are forcibly pulled toward the operator, around needle guard 46 and folder 48, then rotated to be headed away from the operator and toward folder 48, then fed through the folder 48 to create the folds at the edges, and then fed to the needles with the slide fastener tape 56. The direction of such manipulation is indicated generally by the broken lines in FIG. 1. According to this specification of the Adams patent, the needle guard is an important feature of the equipment that is used with the claimed method because it prevents the middle part of body portion 30 from tangling with needles 44 while side edges 30a and 30b are forcibly drawn upstream around the needles to position them for feeding to the needles.
As will be appreciated immediately by persons of skilled in the art, the required forcible turning and feeding of fabric piece 30 will likely be easier with knitted fabric than with woven fabric. However, if fitted fabric is thus pulled and stretched along the edges, particular care must be taken in feeding it through folder element 48 and in correspondence with fastener tape 56 to avoid crinkling, bunching, or buckling of the folder fabric with respect to the fastener tape. If fabric piece 30 is made of a conventional woven fabric, since such fabric at the time of handling will be new and relatively stiff, the operator will have a somewhat different set of handling problems to cope with.
German Patent No. 1,918,719 (now expired), titled "Bed Linen Production With Simultaneously Sewn Slide Fasteners", discloses apparatus and a method for attaching elongate slide fasteners to elements of bed linen, e.g., pillow-cases, bedspreads and the like. The elongate slide fastener tape is fed underneath folded parallel edges of a one-piece length of fabric as folded edges of the fabric are fed thereover to parallel cooperating needles. In the most relevant form of the disclosed apparatus and method, per FIG. 3 of this application (a reproduction of FIG. 5 of the German reference), a long length of fabric, probably several tens of meters in length and initially stored on a bolt 5, is fed in a forward direction underneath an arm of sewing machine 1 and the elongate outer edges of the fabric are brought together and passed through folder elements 9,9. The folded edges of the fabric are thus fed in correspondence with an elongate sliding fastener tape 7 fed therebelow, so that the fastener tape and the folded edges of the fabric together pass under sewing machine head 3 and needles 12, 12 at a matching speed. It is clear from FIG. 3 that this method has merit where very long lengths of fabric are to be processed with a correspondingly long length of fastener element in an automatic manner. Persons skilled in the art will appreciate from FIG. 3 that if the fabric has a printed or patterned face, that face is fed to the sewing machine in a "face down" manner. Furthermore, the elongate fastening element tape is fed underneath the folded edges of the fabric. Since it is very important that the sewn edges of the fastener element tape be correctly sewn to the folded over edges, this method may not be convenient for handling of individual workpieces by a human operator.
As indicated above, Adams requires the operator to apply a force to turn the fabric edges in such a manner as to cause stretching at the sewn edges of the fabric, and the German reference teaches a method in which the tape element is fed underneath the folded edges of the continually fed length of fabric in an automatic feed method which may not be convenient for a human operator handling individual workpieces.
There is, therefore, a present need for a method which enables a human operator to handle a one-piece, seamless body portion of a garment to attach to folded edges thereof a sliding fastener type tape element conveniently, quickly, and without the application of undue handling forces to the edges of the fabric, while being able to observe the alignment, correspondence, and orientation of the fastener element being fed to a pair of cooperating sewing needles.